Pesticidal compositions containing bis (o, o-dialkyl dithiophosphoro-) alkylethers and alkylsulfides



ire

ice

PESTIClDAL COMPOITIONS CONTAINING BIS (0,0-D1ALKYL D1TH10PHQPHORO-)ALKYL- ETIERS AND ALKYLSULFIDES Sidney B. Richter, Chicago, 111.,assignor to Velsicol Chemical Corporation, Chicago, 111., a corporationof Illinois No Drawing. Filed Sept. 30, 1960, Ser. No. 59,482

14 Claims. (Cl. 167-22) This invention relates to new chemicalcompositions of matter and is a continuation of my copending applicationSerial No. 797,582, now abandoned. More specifically, this inventionrelates to new chemical compounds of the general formula wherein X isselected from the group consisting of sulfur and oxygen, n is a wholenumber from to 1, and R is a saturated aliphatic hydrocarbon radicalcontaining from 1 to 3 carbon atoms. These new compounds, useful aspesticides, are the 2:1 addition products of dialkyl phosphorodithioatesHS(S)P(OR) (R is as defined above) with divinyl ether, diallyl ether,divinyl sulfide, or diallyl sulfide.

The new compounds of this invention can be prepared readily by theaddition of two molecular proportions of the dialkyl phosphorodithioateto each molecular proportion of the ether or sulfide employed. Whilethese are satisfactory proportions of reactants, it is preferred to usea slight excess of the dialkyl phosphorodithioate. The reaction can becarried out satisfactorily in the absence of a solvent, but relativelyinert solvents or diluents such as benzene, xylene, or toluene can beused if desired. It is also desirable to add a small amount of anoxidation in hibitor such as hydroquinone to the reaction mixture. Thereaction temperature is not critical, but reaction tempera tures in therange from about normal room temperature to about 75 C. (or the refluxtemperature of the solvent or diluent, if one is used) are preferred.While the exact reaction time is dependent on a variety of factors, theaddition reactions are generally complete within 24 hours. When thereaction is completed, the reaction mixture is cooled and taken up in asuitable solvent, if one has not already been used to run the reaction.The solution is then washed, first with a dilute aqueous solution of abase such as sodium carbonate to remove any excess acid reactant, andthen with water. The solution is dried over an anhydrous drying agentsuch as sodium sulfate, and filtered. The solvent is then distilled oftin vacuo to leave a residue of the desired addition product, which isoften sufficiently pure for pesticidal use without further purification.If desired, however, it can be purified by fractional distillation orother techniques known to those skilled in the art.

Compounds of this invention in which X is sulfur are obtained by usingeither divinyl sulfide or diallyl sulfide as the reactant with thedialkyl phosphorodithioate, while compounds in which X is oxygen areobtained by using either divinyl ether or diallyl ether. When one of thedivinyl compounds is used, 12 in the compounds of this invention is 0;when one of the diallyl compounds is used, It is l.

The manner in which the new compounds of this invention can be preparedis illustrated in the following examples.

2 EXAMPLE 1 Preparation of the 2:] Addition Product of 0,0-DimethylPhosphorodithioate and Diallyl Sulfide A mixture of diallyl sulfide (23g; 0.2 mole) and 0.1 g. hydroquinone was placed in at 250-1111.,round-bottomed flask fitted with a reflux condenser, mechanical stirrer,and internal thermometer. It was then treated in portions with0,0dimethyl phosphorodithioate g.; 0.5 mole), and the mixture wasgradually heated to a temperature of 57 C. The conditions weremaintained overnight, after which the temperature was raised to 70 C.for 7.5 hours. Work-up of the reaction mixture at this point indicatedthat the reaction was not yet complete. Hence an additional 20 g. of0,0-dimethyl phosphorodithioate was added, and the mixture was heated at69 C. for 16.5 hours. The mixture was then cooled, dissolved in benzene,washed first with 200 ml. of 10% aqueous sodium carbonate solution andthen with water, dried over anhydrous sodium sulfate, and filtered. Thebenzene was then distilled off in vacuo (final traces with a mechanicalvacuum pump), and the residue was filtered through Filter-Celdiatomaceous silica filtering aid to give 58 g. ofbis(2-0,0-dimethylphosphorodithio)-propyl sulfide, a viscous oil havingan index of refraction (D line) at 20 C. of 1.5648.

Analysis for C H O P S Theory: S, 37.24%; P, 14.41%. Found: S, 37.31%;P, 14.12%.

Other useful compounds within the scope of this invention can beprepared in the manner detailed above. Given in the following examplesare the reactants required to prepare the indicated named compounds ofthis invention.

EXAMPLE 2 Divinyl ether-i-0,0-dimethyl phosphorodithioate=bis1-0,0-dimethylphosphorodithio)ethyl ether.

EXAMPLE 3 Divinyl ether+0,0 di n propylphosphorodithioate=bis(0,0-di-n-propylphosphorodithio)ethyl ether.EXAMPLE 4 Divinyl ether+0,0 diethyl phosphorodithioate=bis1-0,0-diethylphosphorodithio) ethyl ether.

EXAMPLE 5 Divinyl sulfide+0,0-diethyl phosphorodithioate=bis l-0,0-cliethylphosphorodithio) ethyl sulfide.

EXAMPLE 6 Divinyl sulfide-l-QO-diisopropyl phosphorodithioate =bisI-0,0-diisopropylphosphorodithio)ethyl sulfide.

EXAMPLE 7 Diallyl ether+0,0-dimethyl phosphorodithioate=bis(2-0,0-dimethylphosphorodithio)propyl ether.

EXAMPLE 8 Diallyl ether+0,0 diethyl phosphorodithioate=bis(2-0,0-diethylphosphorodithio)propyl ether.

EXAMPLE 9 Diallyl ether+0,0 di n propyl phosphorodithioate bis(2-0,0-di-n-propylphosphorodithio propyl ether.

EXAMPLE 10 Diallyl -sulfide+0,0-diethyl phosphorodithioate=bis(2-0,0-diethylphosphorodithio)propyl sulfide.

EXAMPLE 11 Diallyl sulfide+0,0 di n-propyl phosphorodithioate =bis(20,0-di-n-propylphosphorodithio)propyl sulfide. EXAMPLE 12 Etivinylsulfide+0,0 dimethyl phosphorodithioate =b1sl-0,0-dimethylphosphorodithio) ethyl sulfide.

in the form of dusts.

The new compounds of this invention are useful as pesticides,particularly as insecticides and miticides. This was illustrated, forexample, in experiments carried out to demonstrate the residual toxicityof test compounds to houseflies. Two milliliters of an acetone solutionof each chemical, prepared at various concentrations, were applied to a125 mm. filter paper. After the solvent had volatilized, the housefiieswere caged in hemispherical wire mesh cages over the treated filterpaper for 24 hours and then observed for mortality. Three replicateswere used for each level of application. In these experiments, theproduct of Example 1 used at a concentration of 1% gave 80.6% mortalityof the houseflies, while there was no mortality in an untreated control.

Experiments were also carried out for the systemic control of thetwo-spotted spider mite (Tetranycims bimaculatus) by root absorption andtranslocation. The test compounds were dissolved in acetone and thendispersed in water at various concentrations of the actual chemical.Host plants, infested with mixed life stages of the mites, wereuprooted, washed free of soil, and placed in glass jars containing 100cc. of the dispersed test compound. Aluminum foil was then placed aroundthe plant stem and jar to reduce possible escape of toxic vapors fromthe test dispersion. The test plants were maintained in the greenhousefor seven days and then observed for systemic miticidal effectiveness.Three replicates were used for each treatment. In these experiments, theprodnot of Example 1 used at a concentration of 100 p.p.m. gave 100%mortality of the mites with no plant injury, while there was only 1.8%mortality in an untreated control.

Similar experiments were carried out for the systemic control of adultpea aphids (Macrosiphum pisi) by root absorption and translocation. Theexperiments were carried out in the same manner described above for thespider mite, except that the test plants were maintained in thegreenhouse for 72 hours before observation of systemic aphicidaleffectiveness. In these experiments, the product of Example 1 used at aconcentration of only 50 p.p.m. gave 100% mortality of the aphids withno plant injury while there was only 7.1% mortality in an untreatedcontrol.

Pesticidal compositions of this invention are prepared by mixing one ormore of the new compounds of this invention with inert carriers toprovide formulations adapted for ready and efficient application withconventional applicator equipment to the site of the pest infestation.For example, pesticidal compositions or formulations according to thisinvention are prepared in the form of solids or liquids. Solidcompositions are preferably These are prepared to give homogeneous,free-flowing dusts by admixing the active compound or compounds of thisinvention with finely divided solid such as the talcs, natural clays,pyrophyllite, diatomaceous earth, fuliers earth, or flours such aswalnut shell, Wheat, redwood, soya bean, or cottonseed flours. Otherinert solid carriers of the type ordinarily used in preparing pestcontrol compositions in dusts or powdered form can also be used.

Liquid compositions according to this invention are prepared by admixingone or more of the new compounds of this invention with a suitable inertliquid diluent. In some cases the compounds are sufiiciently soluble inthe common pesticide solvents such as kerosene, cylene, fuel oil, thealkylated naphthalenes, and the like so that they can be used directlyas solutions in these substances. However, the pesticidal compositionsof this invention can also contain a surface-active agent of the kindused in the art to enable the active compounds to be readily dispersedin water or other liquids to give sprays, which are a preferred methodof applying the active compounds of this invention. The surface-activeagents can be of the anionic, cationic or nonionic types.

Typical examples of such surface-active agents are sodium stearate,potassium laurate, morpholine oleate, sodium lauryl sulfate, sodiumZ-ethylhexyl sulfate, sodium naphthalene sulfonate, sodiumalkylnaphthalenesulfonate, sodium sulfosuccinate, sodium oleic acidsulfonate, sodium castor oil sulfonate, glycerol monostearate containinga soap (or a sodium fatty alcohol sulfate), lithium stearate, magnesiumoleate, aluminum stearate, methyl cellulose, sodium salt ofligninsulfonic acid, polyoxyethylene fatty alcohol ethers, polyglycolfatty acid esters, polyoxyethylene modified fatty acid esters,polyoxyethylene-polyol fatty acid esters, polyoxypropylene fatty alcoholethers, polypropylene glycol fatty acid esters, polyoxypropylenemodified fatty acid esters, polyoxypropylenepolyol fatty acid esters,polyol fatty acid monoesters, lecithin, diand higher polyhydric alcoholfatty acid esters, cholesterol and other fatty acid esters, lanolin,oxidized fatty oils, quaternary ammonium salts such as lauryl dimethylbenzyl ammonium chloride, amine hydrochlorides such as laurylaminehydrochloride, alkylated aryl polyether alcohols such as thecondensation product of diamylphenol with ethylene oxide, and the like.Mixtures of such agents can be used to combine or modify properties. Theproportion of these agents will ordinarily vary from about 1% or less toabout 15% by weight of the pesticidal compositions. Other pesticides aswell as such substances as fertilizers, activators, adhesives,spreaders, and synergists can be added to these formulations if desired.The manner in which typical pesticidal compositions according to thisinvention can be prepared is illustrated in the following examples. Allquantities given are in parts by weight.

EXAMPLE 13 Preparation of an Emulsifiable Concentrate The followingingredients are blended thoroughly until a homogeneous liquidconcentrate is obtained. This concentrate is mixed with water to give anaqueous dispersion containing the desired concentration of activecompound for use as a spray.

Bis(2-0,0-dimethylphosphorodithio)propyl sulfide 25 Sodium laurylsulfate ,2

Sodium lignin sulfonate 3 Kerosene 70 EXAMPLE 14 Preparation of a Wettable Powder The following components are mixed intimately inconventional mixing or blending equipment and are then ground to apowder having an average particle size of less than about 50 microns.The finished powder is dispersed in water to give the desiredconcentration of active compound.

Bis(2-0,0-diethylphosphorodithio)propyl sulfide 75.00 Fullers earth22.75 Sodium lauryl sulfate 2.00 Methyl cellulose .25

EXAMPLE 15 Preparation of an Oil-Dispersible Powder The followingcomponents are blended and ground as describedin the previous example togive a powder which can be dispersed in oil to form a spray containingthe desired concentration of active compound.

Bis(2-0,0-dimethylphosphorodithio)propyl ether 70 Condensation productof diamylphenol with ethylegg oxide Fullers earth EXAMPLE 16 Preparationof a Dust The following ingredients are mixed thoroughly and then groundto an average particle size of less than about 50 microns to give a dustsuitable for application with conventional dusting equipment.

Bis(1-0,0-dimethylphosphorodithio)ethyl sulfide 20 Talc 80 EXAMPLE 17Preparation of a Granular Formulation The following ingredients aremixed with sufiicient water to form a paste, which is then extruded,dried, and ground to give granules, preferably from about to 4 inch indiameter. The granules are applied with fertilizer spreader equipment orother conventional apparatus. The dextrin in this formulation serves asa binding agent.

Bis(1-0,0-dimethylphosphorodithio)ethyl ether Fullers earth 66 DextrinSodium lignin sulfonate 3 Kerosene 1 lclaim:

9. An insecticidal and miticidal composition comprising an inert carrierand a toxic amount of a compound of claim 1.

10. A method of destroying undesirable insects and mites which comprisescontacting these pests with an insecticidal and miticidal compositioncomprising an inert carrier and as the essential active ingredient, in aquantity which is toxic to said pests, a compound of claim 1.

.11. A process for the preparation of a compound as described in claim=1 which comprises reacting at least two molecular proportions of acompound of the general formula HS(S)P(OR) wherein R is a saturatedaliphatic hydrocarbon radical containing from 1 to 3 carbon atoms, withone molecular proportion of a compound selected from the groupconsisting of divinyl ether, diallyl ether, divinyl sulfide, and diallylsulfide.

12. A process as described in claim 11, wherein the reaction is carriedout in the presence of a relatively inert solvent and at a temperaturewhich is the reflux temperature of said solvent.

13. A process which comprises reacting at least two molecularproportions of 0,0-dimethyl phosphorodithioate with one molecularproportion of diallyl sulfide.

14. A process which comprises reacting at least two molecularproportions of 0,0-dimethyl phosphorodithioate with one molecularproportion of diallyl sulfide at a temperature of from about 57 to aboutC., dissolving the reaction mixture in a relatively inert solvent, andremoving therefrom the compound bis(2-0,0-dimethylphosphorodithio)propylsulfide.

References Cited in the file of this patent UNITED STATES PATENTS2,596,076 Hook et a1 May 6, 1952 2,884,353 Christman Apr. 28, 19592,884,354 Christman Apr. 28, 1959' 2,885,430 Scherer et a1. May 5, 1959FOREIGN PATENTS 515,666 Canada Aug. 16, 1955

1. A COMPOUND OF THE FORMULA